1,720,977 research outputs found
The predatory impact of Dikerogammarus villosus, a danger for fish.
No full textQuesto anfipode gammaride è arrivato in Europa dalla
sua zona di origine, la Ponto-Caspiana, dopo l’apertura
dei canali di collegamento Danubio-Meno-Reno nel 1992,
e in pochi anni si è rapidamente distribuito nella rete
fluvio-lacustre centro-europea.
Ovunque si è insediato ha spiazzato altre specie di crostacei
native, con profonde alterazioni della comunità di
macroinvertebrati. E' stato dimostrato in esperimenti di laboratorio che preda anche le uova di pesce, preferendole ad altre pred
Prototype of piezoelectric valve with nozzle for space propulsion applications
No full textThis manufact is the prototype of the main component of a thruster for small and very small thrusts for the precision orbital positioning of scientific satellites. The design was performed in cooperation with Thales Alenia Spazio, who, based on this prototype, built the flight thrusters. The prototype is fully functioning and allowed to validate the design concept and to test the performance
Dikerogammarus villosus (Sowinsky, 1894) a new invasive species in the Garda Lake (Northern Italy)
No full textDikerogammarus villosus (Sowinsky, 1894) (Crustacea, Amphipoda, Gammaridae) for the first time in Italy
No full textThe recent discovery in Lake Garda, and in other watercourses of northern Italy, of Dikerogammarus villosus, an amphipod crustacean from the Ponto-Caspian region, is a worrying confirmation of how it is rapidly spreading in Europe. In Lake Garda, the species is present, with high population density, in the southern basin, where it is the only gammarid of the littoral benthos, and in the northern basin, with lower population density, where it still coexists with the native species Echinogammarus stammeri. Ovigerous females and juveniles are present most of the year in all the explored areas. Considering that the species has often replaced the native gammarids in invaded waters in most European regions, we want to raise the alarm for a possible progressive elimination of the native species E. stammeri by the invading one from the Garda littoral benthos
The alien amphipod crustacean Dikerogammarus villosus in Lake Garda(N-Italy): the invasion continues.
No full textThe discovery of Dikerogammarus villosus, an amphipod crustacean from the Ponto-Caspian region, on the shores of Lake Garda and in other watercourses of northern Italy, is a worrying fact that deserves attention. In the littoral environment of this lake, D. villosus interacts with Echinogammarus stammeri, one of four indigenous gammarid species, which shares a similar microhabitat. According
to a previous study in 2003-2004, the invasive species had expanded throughout the shallow zone ofthe lake quite rapidly, particularly in the southern basin, competing with the indigenous gammarid species which it may even replace. In order to monitor the situation in time, this study was done in
2006 to investigate the distribution of the two gammarid species at various depths (1, 2, 5, 10 m) in
the littoral zone, and to verify the hypothesis suggested by previous work that E. stammeri is spatially segregated from D. villosus. The indigenous species was found to be mostly relegated to greater depths, thus reducing unfavourable interactions with the invader. It is a matter of particular concern that also D. villosus is moving deeper, with possible adverse effects resulting from niche overlaps
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Long-term non-invasive ventilation increases chemosensitivity and leptin in obesity-hypoventilation syndrome
No full textBackground: Long-term nocturnal non-invasive mechanical ventilation (NIMV) is an
effective treatment for obesity-hypoventilation syndrome (OHS), improving central carbon
dioxide (CO2) sensitivity. Leptin might contribute to sustain adequate ventilation in
obesity. The aim of the study was to investigate the role of leptin in the OHS pathogenesis
looking at its relationship to CO2 sensitivity before and after NIMV in OHS patients.
Methods: In six obese patients (3F/3M; aged 6379 yr; BMI 47.074.5 kg/m2) with OHS and
without obstructive sleep apnoea–hypopnoea (OSAH) diurnal arterial blood gases, fasting
plasma leptin concentration and CO2 chemosensitivity were determined before and after
10.375.6 (range 6–20) months of NIMV.
Results: After NIMV improvements were observed in gas exchange (PaO2 from 51.376.7 to
75.0710.3 mmHg, po0.01; PaCO2 from 55.574.8 to 43.771.2 mmHg, po0.01; [HCO3 ]
from 33.373.8 to 29.871.7 mmol/l, po0.05) and CO2 chemosensitivity, measured as P0.1/
PetCO2 slope (from 0.0970.07 to 0.1870.07 cmH2O/mmHg, po0.05) and VE/PetCO2 slope
(from 0.470.3 to 0.970.5 l/min/mmHg, p1⁄4 0:07). Plasma leptin increased from
34.5721.1 ng/ml to 50.2722.9 ng/ml (po0.01) after NIMV and changes of the P0.1/
PetCO2 slope correlated with percent changes of plasma leptin (r2 1⁄4 0:79, po0.05).
Conclusions: These findings suggest a possible role of leptin in the recovery of
neuromuscular response to hypercapnia obtained during long-term nocturnal NIMV in
OHS patients without OSAH
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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